Calcium plays an important role in blood coagulation, nerve transmission, muscle contraction, and heart function. Protection against high blood pressure, colon cancer, and the degenerative bone disease known as osteoporosis have been attributed to calcium. Calcium is required in the diet in relatively large quantities. The Food and Nutrition Board has established a Dietary Reference Intake (DRI) for calcium. A daily intake of about 1000 mg of calcium meets most peoples needs for general health especially bone health. For older adults and people with osteoporosis many clinicians recommend a daily intake of about 1200 mg of calcium. Calcium requirements in adolescent children and lactating and pregnant women are 1000-1300 mg daily. The published DRIs list the recommended DRI by age. The daily adult upper limit “UL” of calcium is 2500 mg. See www.nal.usda.gov. However, the average calcium intake may be only about one-third to one-half of the recommended daily dosing. Thus, dietary supplementation of calcium is beneficial. If dietary sources of calcium do not provide sufficient amounts of calcium to the blood, calcium is depleted from the bones to compensate for the insufficient amounts. Age related bone loss and fracture rates in patients with osteoporosis may be reduced with high dietary intake of calcium. Calcium absorption efficiency decreases with increasing intake. Calcium absorption efficiency is greater if calcium is ingested in divided doses.
The ability of different individuals to utilize the calcium in food may vary considerably. For example, a high protein diet may result in about 15% of the dietary calcium being absorbed, whereas a low protein diet may result in only about 5% of the dietary calcium being absorbed. Moreover, changes in dietary protein in humans alter urinary calcium excretion. Increased protein consumption results in increased calcium excretion (Kerstetter, et al., Am J Clin Nutr 1998; 68:859-865). Certain compounds in food may interfere with calcium absorption. Intestinal factors that influence the absorption of calcium include pH, the calcium:phosphorus ratio, the presence of free fatty acids which occurs when fat absorption is impaired, and the amount of vitamin D. Generally, the more alkaline the contents of the intestines, the less soluble are the calcium salts. Also, a high calcium:phosphorus ratio favors the formation of tricalcium phosphate rather than the more soluble, better absorbed forms. If either calcium or phosphorus is taken in excess, excretion of the other is increased. The optimal ratio is 1:1 when the intake of vitamin D is adequate. Vitamin D promotes the absorption of calcium from the intestine. Calcium citrate has been shown to have two independent mechanisms for calcium absorption, one is vitamin D dependent and one vitamin D independent (Favus and Pak; Am J of Therapeutics 2001; 8:425-431). Many nutritionists believe that the current recommended daily levels of Vitamin D3 (400 IU) are too low and advise higher levels.
Although milk has been a major source of calcium for infants and young children, many teenagers and adult Americans are consuming lesser amounts of it. The calcium content of milk and other beverages can be increased to facilitate meeting the U.S. DRIs for calcium. Calcium enrichment of other foods such as bean curd, yogurt, and cereal grains is disclosed in U.S. Pat. Nos. 4,676,583, 4,784,871, and 4,765,996, respectively.
Calcium compounds have been utilized in baked goods such as crackers, as components of leavening agents, as pH adjusters, in yeast foods, and for its nutritive value. However, calcium-fortified baked goods typically have a dry mouth feel, a dry and hard texture and a very chalky taste as compared to a noncalcium-fortified baked product.
U.S. Pat. No. 5,514,387 is directed to calcium-enriched baked goods and teaches the tenderization of calcium-enriched crackers and other baked goods in which the dough includes an emulsifying amount of at least one poly-oxyethylene sorbitan fatty acid ester and at least one stearoyl lactylate. U.S. Pat. No. 4,196,226 discloses a leavening acid comprising alkali metal aluminum phosphate granules having a calcium rich outer surface for improving flow and dusting properties. U.S. Pat. Nos. 6,495,191 and 6,126,982 disclose wheat flour for mineral-enhanced bakery products having at least an additional 2-20% by weight of dietary minerals.
It would be desirable to have a chewable calcium-enriched baked food product that meets the requirements for a Dietary Supplement that has acceptable mouth feel, appearance, taste, aroma, and texture in which at least one piece of the food product provides the recommended daily DRI of calcium and a Vitamin D3 range of 100-2400 IU.